but so does warmogs

pls help riot

Erm, it's pretty simple solution, IMO.

If they're stacking health, you counter by getting spellvamp as LB. Single target spells get full use of spellvamp, and single target hits are what she excels at. Combined with Liandry's Torment (and Rylai's if you need to be semi-tanky to survive trades), and they'll regret stacking health.

A void staff/Liandry's is usually enough to counter hexdrinker. The idea is, you CAN counter Leblanc by building survivability, but doing so lowers your damage, and thereby making you useless. So yeah, there's going to be people who intentially build against you, so just outsmart them by using these items. You only deal average damage, but that's probably tons more than they can do.

the problem with these utility counter items are they dont give enough offensive stats to be worth their high costs, bursts casters have no actually counters to HP+MR combo, never have either. your not likely to deal any significant damage even with void and torment/DFG. given most burst mages have a long waiting period before another combo these beefy champs have plenty of time to just sustain their back up and negate any damage.

a hexdrinker on top of that is just a kick in the teeth

Uhm, sorry? What do you expect exactly? For you to be able to 1-combo and burn down any champion with them having no counter options at all?

Leblanc has pretty decent range and she can easily teleport in, double sigel, chain, then teleport out if they gapclose on her. Even if hexdrinker saves them, it has a long CD. What exaclty is preventing you from...you know...trying it again later?

Stop going for a kill when you should not be might be the answer to a limited degree. If you know they have a hexdrinker or maw of malmortis, you need to hold off on your R until you know it will be effective and get you the kill you want.

In the end, LeBlanc has always been an early to mid game boss, that plays a more clean-up role in late game unless you get fed and can snowball, but a long game counters her pretty well. Plus, Leblanc is a great roamer so you can possibly bounce from mid lane to top or bottom to assist in getting kills or pushing your team ahead. I really do not see Warmog / hexdrinker being the end of Leblanc, just something you need to play to overcome.

If they have twice as much health, then you combo them twice. LB has the tools to walk away after unloading. There's no rule anywhere that says you HAVE to get a kill every time you push all the buttons. If you watch any high-Elo LB players, they don't expect to 100-0 anyone but the squishiest of squishies. If it's a bruiser or a tank, then they'll hit em hard once, and then maneuver until they can finish the job.